HIGH-ENERGY INELASTIC NEUTRON-SCATTERING FROM PHYSISORBED HYDROGEN IN CESIUM INTERCALATED GRAPHITE

被引:10
作者
KELLOGG, GJ
WHITE, JW
HERWIG, KW
SOKOL, PE
机构
[1] AUSTRALIAN NATL UNIV,RES SCH CHEM,CANBERRA,ACT 2600,AUSTRALIA
[2] PENN STATE UNIV,DEPT PHYS,UNIVERSITY PK,PA 16802
关键词
D O I
10.1063/1.459439
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
The inelastic neutron scattering from H2 in C 24Cs(H2)x has been measured at momentum transfers of 8 < Q < 22 Å-1 as a function of filling, 0.5 < x < 2.0, and temperature from 20 to 150 K. The observed scattering approaches the limiting behavior predicted by the Impulse Approximation (IA) for molecular hydrogen for Q''s greater than 15 Å-1 and is insensitive to the filling factor and temperature up to kT/M≈0.1, where M is the enthalpy of hydrogen sorption. The results are analyzed using a model for the IA scattering from molecular hydrogen which takes into account the excitation of rotational transitions and the presence of a local orientational potential at the hydrogen adsorption sites. The average translational kinetic energy per molecule, which is determined by the effective local potential for the molecule, can be extracted from the measured scattering. For a powder sample, such as used in this measurement, determination of the kinetic energy requires independent knowledge of the orientational potential of the H 2 molecules. Using the orientational potential inferred from previous tunneling measurements we extract an average translation kinetic energy of 320 K for the H2 molecule in the intercalate. © 1990 American Institute of Physics.
引用
收藏
页码:7153 / 7162
页数:10
相关论文
共 22 条
[1]  
BEAUFILS JP, 1981, MOL PHYS, V44, P257
[2]  
BOWDIN ZA, 1988, CHEM PHYS LETT, V147, P228
[3]  
HERWIG KW, 1989, MOMENTUM DISTRIBUTIO
[4]   HIGH-ENERGY NEUTRON SCATTERING FROM LIQUID HE4 [J].
HOHENBERG, PC ;
PLATZMAN, PM .
PHYSICAL REVIEW, 1966, 152 (01) :198-+
[5]   DOMAIN MOBILITY AND ROTATIONAL TUNNELING OF HYDROGEN IN GRAPHITE INTERCALATES [J].
JACKSON, IP ;
WHITE, JW .
CHEMICAL PHYSICS LETTERS, 1987, 134 (05) :397-399
[6]  
JACKSON IP, 1988, J CHEM SOC F2, V84, P1169
[7]  
JANIK JA, 1965, THERMAL NEUTRON SCAT, P413
[8]   INELASTIC NEUTRON-SCATTERING FROM LIQUID AND SOLID HYDROGEN AT HIGH MOMENTUM-TRANSFER [J].
LANGEL, W ;
PRICE, DL ;
SIMMONS, RO ;
SOKOL, PE .
PHYSICAL REVIEW B, 1988, 38 (16) :11275-11283
[9]  
Press W. H., 1992, NUMERICAL RECIPES EX
[10]  
PRICE DL, 1982, UNPUB 6TH P M INT CO, P207